In the years before World War I, Bartók traveled the countryside in Hungary and surrounding areas collecting and cataloging folk songs, and even recording them. The bulky, awkward recording equipment of the time made such a project challenging even for a strong, healthy person, which Bartók was not. Nonetheless, he went to Transylvania, Bulgaria, Ruthenia, and even North Africa in his ethnomusicological quests. For a while, the war got in the way of his efforts, but after he had been excused from military service for health reasons, the government pressed him into service anyway, and sent him and Zoltán Kodály into army camps to collect folk songs from soldiers.
All this folkloric activity had a greater effect on Bartók than simply giving him a lot of new tunes. Much of the music he studied stood outside the mainstream European tradition, using scales other than major or minor and modes of accompaniment other than the harmony that he had learned at the Budapest Academy. Even as he became aware of Schoenberg's atonal music and Stravinsky's new works in the prewar years, Bartók's immersion in folk music led to his own kind of avant-garde, different from everyone else's.
The Second String Quartet, completed in 1917, shows the range and variety of Bartók's new style. The first movement opens with a leaping motif based on the interval of a seventh - a quintessentially atonal figure. But it intertwines with tonal themes, including a strikingly tender minor-key motif that has a strongly medieval quality. Kodály, who thought of the three movements of this quartet as "life episodes," heard "peaceful life" in the first movement, and for all its roiling emotions, the movement does indeed leave an impression of tranquility at the end. The experience of listening to the movement is different from the experience of having listened to it.
The second movement puts Bartók's "barbaric" style on display. Serious Bartókians will tell you that that the melodic material owes much to the Arabic music the composer studied on his North African trip, but a Hungarian accent is also unmistakable. Bartók, like a one-man microcosm of music history, assimilated and combined disparate styles and cultures and made them his own.
When someone asked Bartók to analyze the form of the Quartet's middle movement, he called it "a kind of rondo, with a developmental section in the middle." Listeners will more likely hear a sort of ABA form: a movement of frantic intensity and velocity that rests for a while in a middle section where short episodes marked "more tranquil" alternate with others marked "less tranquil."
The brooding, intense last movement (Kodály heard it as "suffering") is particularly funereal because it is as immobile as the second movement is animated. Long stretches are rhythmically static, and the parts that do move are often interrupted by silence.
— Howard Posner has also written program notes for the Los Angeles Baroque Orchestra, the Coleman Concerts, and the Salzburg Festival.